Disclosure of Invention
The present invention is directed to a system and a method for protecting a refrigerator of a nuclear power plant, which overcome the above-mentioned drawbacks of the prior art.
The technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides a nuclear power plant's refrigerator protection system, includes at least one refrigerator, is provided with differential pressure switch and the cooling water valve that is located the low reaches of refrigerator on the cooling water pipeline of every refrigerator, on the same cooling water pipeline differential pressure switch, cooling water valve connect the refrigerator controller that the refrigerator on this cooling water pipeline corresponds via a protection signal output module respectively, protection signal output module is used for outputting control signal to the refrigerator controller that opens and close as the refrigerator according to cooling water valve and differential pressure switch's state.
The two sampling ports of the differential pressure switch are respectively connected with two sampling branches positioned at the upstream and downstream of the refrigerator.
The differential pressure switch outputs an effective cut-off signal when the differential pressure between the two sampling ports reaches a preset differential pressure value;
and the protection signal output module outputs a control signal to the refrigerator controller to control the refrigerator to stop working when receiving that the valve full-opening position signal is invalid or the cutoff signal is valid.
Preferably, the protection signal output module is an and logic module, the full-open position signal represents valid when the signal is logic 1 and represents invalid when the signal is logic 0, the differential pressure switch selects a normally open contact, and the cutoff signal represents valid when the signal is logic 1 and represents invalid when the signal is logic 0;
the AND logic module is used for performing AND logic on the full-open position signal and the inverted cutoff signal and outputting a control signal to the refrigerator controller, and the refrigerator controller is used for controlling the refrigerator to stop refrigerating when the control signal is logic 0.
Preferably, the protection signal output module is an and logic module, the full-open position signal represents valid when the signal is logic 1 and invalid when the signal is logic 0, the differential pressure switch selects a normally closed contact, and the cutoff signal represents valid when the signal is logic 0 and invalid when the signal is logic 1;
the AND logic module is used for performing AND logic on the full-open position signal and the cutoff signal and then outputting a control signal to the refrigerator controller, and the refrigerator controller is used for controlling the refrigerator to stop refrigerating when the control signal is logic 0.
The number of the refrigerators is three, and under a normal condition, two refrigerators in the three refrigerators run and one refrigerator is standby.
The invention also discloses a method for protecting the refrigerating machines of the nuclear power plant, which is applied to a system comprising at least one refrigerating machine, wherein a cooling water valve positioned at the downstream of the refrigerating machine is arranged on a cooling water pipeline of each refrigerating machine, and the method comprises the following steps:
a differential pressure switch is arranged on a cooling water pipeline of each refrigerator, and the differential pressure switch and a cooling water valve on the same cooling water pipeline are respectively connected with a refrigerator controller corresponding to the refrigerator on the cooling water pipeline through a protection signal output module;
and the protection signal output module outputs a control signal for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch.
The two sampling ports of the differential pressure switch are respectively connected with two sampling branches positioned at the upstream and downstream of the refrigerator.
The cooling water valve outputs a valve full-open position signal when being opened, and the differential pressure switch outputs a cut-off signal when the differential pressure between the two sampling ports reaches a preset differential pressure value;
and the protection signal output module outputs a control signal to the refrigerator controller to control the refrigerator to stop working when receiving that the valve full-opening position signal is invalid or the cutoff signal is valid.
Preferably, the protection signal output module is an and logic module, and the full-open position signal represents valid when being logic 1 and invalid when being logic 0;
if the differential pressure switch selects a normally open contact, the cutoff signal represents valid when the cutoff signal is logic 1 and invalid when the cutoff signal is logic 0, and the protection signal output module outputs a control signal used for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch, wherein the control signal comprises the following specific steps: the AND logic module performs AND logic on the full-open position signal and the inverted cutoff signal and outputs a control signal to the refrigerator controller, and the refrigerator controller controls the refrigerator to stop refrigerating when the control signal is logic 0;
if the differential pressure switch selects a normally closed contact, the cutoff signal represents valid when the cutoff signal is logic 0 and invalid when the cutoff signal is logic 1, and the protection signal output module outputs a control signal used for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch, wherein the control signal comprises the following specific steps: the AND logic module outputs a control signal to the refrigerator controller after performing AND logic on the full-open position signal and the cutoff signal, and the refrigerator controller controls the refrigerator to stop refrigerating when the control signal is logic 0.
The implementation of the system and the method for protecting the refrigerating machine of the nuclear power plant has the following beneficial effects: the cooling water pipeline is provided with the differential pressure switch, and the states of the cooling water valve and the differential pressure switch can reflect water flow, and the protection signal output module can output a control signal for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Exemplary embodiments of the invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
In order to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to the drawings and the specific embodiments in the specification, and it should be understood that the embodiments and the specific features in the embodiments of the present invention are detailed descriptions of the technical solution of the present application, and are not limited to the technical solution of the present application, and the technical features in the embodiments and the examples of the present invention may be combined with each other without conflict.
Referring to fig. 1, in the present embodiment, there are three refrigerators in total, and two of the refrigerators are on standby. The refrigerating pipeline of each refrigerator is provided with a cooling water valve at the downstream of the refrigerator, and a water valve at the upstream of the refrigerator. As shown in the figure, the 01DEG105VN, the 01DEG205VN and the 01DEG305VN correspond to cooling water valves of three refrigerators, and it is generally considered that if the cooling water valves are opened, the water flow is large; if the cooling water valve is closed, the water flow is small, and refrigeration protection can be performed. Therefore, the refrigeration protection can be carried out by monitoring the valve full-open position signals of the 01DEG105VN, the 01DEG205VN and the 01DEG305 VN. However, the upstream of the three refrigerators also has valves, when the upstream valves are closed, the DEG refrigerator group can completely lose the cooling water, and at this time, the fully-opened position signals of the 01DEG105VN, 01DEG205VN and 01DEG305VN valves obviously cannot represent the cooling water flow signal, so that an alarm that the cooling water flow is low cannot occur. In this case, there is a high possibility that the operating refrigerator is damaged by the complete loss of the cooling water.
Therefore, the differential pressure switch is arranged on the refrigeration pipeline of each refrigerator, two sampling ports of the differential pressure switch are respectively connected with two sampling branches positioned at the upper and lower streams of the refrigerator, and the differential pressure switch outputs an effective cutoff signal when the differential pressure between the two sampling ports reaches a preset differential pressure value (the differential pressure switch has a plurality of gears which can be set). As shown in the figure, 103VYP and 104VYP are two sampling branches upstream and downstream of the first refrigerator, two sampling ports of the first differential pressure switch 01DEG103SP are respectively connected with 103VYP and 104VYP, similarly, two sampling ports of the second differential pressure switch 01DEG203SP are respectively connected with 203VYP and 204VYP, and two sampling ports of the third differential pressure switch 01DEG303SP are respectively connected with 303VYP and 304 VYP.
The differential pressure switch and the cooling water valve on the same cooling water pipeline are respectively connected with the refrigerator controller corresponding to the refrigerator on the cooling water pipeline through a protection signal output module, and the protection signal output module is used for outputting a control signal for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch.
Specifically, when the protection signal output module receives that the valve full-open position signal is invalid or the cutoff signal is valid, the protection signal output module outputs a control signal to the refrigerator controller to control the refrigerator to stop working.
Referring to fig. 2, in the present embodiment, the protection signal output module is an and logic module. Wherein, the full-open position signal represents valid when being logic 1 and invalid when being logic 0.
In this embodiment, the differential pressure switch uses a normally open contact, when water flow is normal, the normally open contact is closed, the differential pressure switch transmits a logic 0 to represent that the cutoff signal is invalid, and when the water flow is low (lower than a preset differential pressure value), the normally open contact is opened, and the differential pressure switch transmits a logic 1 to represent that the cutoff signal is valid. The circuit breaking signal is logic 1 effective, so the circuit breaking signal needs to be inverted and then sent to the AND logic module, the AND logic module outputs a control signal to the refrigerator controller after carrying out AND logic on the fully-open position signal and the inverted circuit breaking signal, and the refrigerator controller is used for controlling the refrigerator to stop refrigeration when the control signal is logic 0.
The working principle of the embodiment is as follows: when the water flow is normal, the full open position signal of the cooling water valve is logic 1 and is directly sent to the logic AND module, the cutoff signal output by the differential pressure switch is logic 0 and is sent to the logic AND module after being inverted, and the output of the logic AND module is logic 1, so that the refrigerating machine cannot be triggered to stop refrigerating. When the water flow is reduced, on one hand, no matter whether the cooling water valve is closed or not, the cutoff signal output by the differential pressure switch is logic 1, and the logic and module outputs logic 0 after being sent to the logic and module after being inverted, so that the refrigerating machine is triggered to stop refrigerating; on the other hand, when the cooling water valve is closed, the fully-opened position signal of the cooling water valve is logic 0 and is directly sent to the logic and module, so that the logic and module outputs logic 0 to trigger the refrigerator to stop refrigerating, and the reliability of protection can be improved.
Of course, a normally closed contact of a differential pressure switch can be selected, and the current breaking signal is directly sent to the AND logic module without being inverted. Specifically, when water flow is normal, the normally closed contact is opened, the differential pressure switch transmits a logic 1 to indicate that a cut-off signal is invalid, when the water flow is low (lower than a preset differential pressure value), the normally closed contact is closed, the differential pressure switch transmits a logic 0 to indicate that the cut-off signal is valid, the AND logic module outputs a control signal to the refrigerator controller after performing AND logic on the fully open position signal and the cut-off signal, and the refrigerator controller is used for controlling the refrigerator to stop refrigerating when the control signal is logic 0.
Based on the same invention concept, the invention also discloses a method for protecting the refrigerating machines of the nuclear power plant, which is applied to a system comprising at least one refrigerating machine, wherein a cooling water valve positioned at the downstream of the refrigerating machine is arranged on a cooling water pipeline of each refrigerating machine, and the method comprises the following steps:
firstly, a differential pressure switch is arranged on a cooling water pipeline of each refrigerator, two sampling ports of the differential pressure switch are respectively connected with two sampling branches positioned at the upper and lower streams of the refrigerator, and the differential pressure switch and a cooling water valve on the same cooling water pipeline are respectively connected with a refrigerator controller corresponding to the refrigerator on the cooling water pipeline through a protection signal output module; wherein, the cooling water valve outputs a valve full-open position signal when being opened, the differential pressure switch outputs a cut-off signal when the differential pressure between the two sampling ports reaches a preset differential pressure value,
and then, after the structure is configured and the refrigerator is put into operation, the protection signal output module outputs a control signal for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch. With regard to the shutdown, in particular: and the protection signal output module outputs a control signal to the refrigerator controller to control the refrigerator to stop working when receiving that the valve full-opening position signal is invalid or the cutoff signal is valid.
In this embodiment, the protection signal output module is an and logic module, and the fully-open position signal represents valid when the fully-open position signal is logic 1 and represents invalid when the fully-open position signal is logic 0. And if the differential pressure switch selects a normally open contact, the cutoff signal represents effective when the cutoff signal is logic 1 and represents ineffective when the cutoff signal is logic 0. The protection signal output module outputs a control signal for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch, specifically: the AND logic module performs AND logic on the full-open position signal and the inverted cutoff signal and outputs a control signal to the refrigerator controller, and the refrigerator controller controls the refrigerator to stop refrigerating when the control signal is logic 0;
of course, if the differential pressure switch is a normally closed contact, the cutoff signal is logic 0, which means valid, and logic 1, which means invalid. The protection signal output module outputs a control signal for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch, specifically: the AND logic module outputs a control signal to the refrigerator controller after performing AND logic on the full-open position signal and the cutoff signal, and the refrigerator controller controls the refrigerator to stop refrigerating when the control signal is logic 0.
In summary, the system and the method for protecting the refrigerating machine of the nuclear power plant have the following advantages: the cooling water pipeline is provided with the differential pressure switch, and the states of the cooling water valve and the differential pressure switch can reflect water flow, and the protection signal output module can output a control signal for starting and stopping the refrigerator to the refrigerator controller according to the states of the cooling water valve and the differential pressure switch.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.